1. Field of the Invention
The present invention relates to a cleaning blade used in electrophotography, which slidingly rubs the surface of a photosensitive member to clean it, and also relates to an apparatus making use of the cleaning blade.
2. Related Background Art
The cleaning blade for electrophotography is a plate-like molded product mainly comprising a polyurethane elastomeric material. The cleaning blade is used for the purpose of physically cleaning and removing the toner adhered to the surface of the photosensitive member, by bringing the blade into contact with the surface. In such an instance, however, the blade must resist the electrostatic attraction force of toner particles, exerted on the surface of the photosensitive member, before it can remove the toner particles from the surface of the photosensitive member. Hence, it must be pressed against the surface of the photosensitive member with great pressure. Thus, great frictional force is produced between the photosensitive member and the cleaning blade, and therefore it may occur that the cleaning blade is turned and reversed, resulting in no cleaning operation, or that the surface is scraped when the photosensitive member is made of a soft material, bringing about defective images or a short life of the photosensitive member.
To solve such problems, measures have been hitherto taken such that a lubricant is applied to the top of a blade or a powder of fluorine resin, such as PTFE, is incorporated into it. However, the method in which a lubricant is applied to the top of the blade can be effective only for a short period of time. The method in which a fluorine resin powder is incorporated into the top of the blade has the disadvantages such that the fluorine resin falls off in the course of cleaning because of an insufficiency of the retention power of rubber to the fluorine resin, resulting in a lowering of the cleaning performance.